In connection with diagnosis of various diseases, such as various cancer diseases, biopsies are taken. When taking a biopsy and no malignant cells are detected, it is important that it can be ruled out that this is not simply due to that the biopsy was sampled from the wrong site. To increase the certainty of the biopsy sampling, guided biopsy may be used. Such guided biopsy sampling can be based on a number of image modalities, examples include X-ray, CT, MRI, ultrasound and optics.
For many purposes optical imaging by use of a miniaturized needle microscope is used. Imaging by use of needle microscopy has the advantage that it does not involve harmful X-rays or the expensive machinery of CT or MRI scanners. Moreover, it supports integration into the biopsy needle itself, thereby allowing direct visual inspection of the biopsy site prior to, during and after the biopsy.
The European patent application no. 1 901 107 A1 discloses an example of a miniaturized confocal needle microscope comprising a vibrating light transmitter, in the form of a fibre, mounted inside a housing, where the vibration of the transmitter executes a scan pattern, the vibration being based on an actuation system comprising electromagnetic coils and permanent magnets.
A problem with a scanning fibre is that if the true position of the fibre end deviates from the set-point position, the image construction introduces artefacts.